Tag Archives: evolution

The mammoth’s extinction may have been our original ecological sin. When humans left Africa 70,000 years ago, the elephant family occupied a range that stretched from that continent’s southern tip to within 600 miles of the North Pole. Now elephants are holed up in a few final hiding places, such as Asia’s dense forests. Even in Africa, our shared ancestral home, their populations are shrinking, as poachers hunt them with helicopters, GPS, and night-vision goggles. If you were an anthropologist specializing in human ecological relationships, you may well conclude that one of our distinguishing features as a species is an inability to coexist peacefully with elephants.

But nature isn’t fixed, least of all human nature. We may yet learn to live alongside elephants, in all their spectacular variety. We may even become a friend to these magnificent animals. Already, we honor them as a symbol of memory, wisdom, and dignity. With luck, we will soon re-extend their range to the Arctic. […]

Nikita and Sergey seemed entirely unbothered by ethical considerations regarding mammoth cloning or geoengineering. They saw no contradiction between their veneration of “the wild” and their willingness to intervene, radically, in nature. At times they sounded like villains from a Michael Crichton novel. Nikita suggested that such concerns reeked of a particularly American piety. “I grew up in an atheist country,” he said. “Playing God doesn’t bother me in the least. We are already doing it. Why not do it better?”

Amanda Glaze

But, again, if you tell people their religious beliefs are obscured, you’re going to have a fight on your hands. What bothers me is the lack of understanding about what science actually does.

Science doesn’t consider God as a possible answer to any question whatsoever because God is a metaphysical construct and thus not part of the physical world. And science by definition cannot consider anything metaphysical or supernatural as an explanation.

Science is not out there trying to disprove the existence of God — we can’t even consider that.

I really don’t care what people believe as long as they understand the science.

Sean Illing

Let me push back on that for a minute.

You say that there’s a perceived conflict between being religious and scientific but that this is a false dichotomy. I think one can certainly be a religious person and a scientist, but can one be both at the same time?

Religions invariably make claims about the world that contradict what science says is true, and so to be engaged in science you have to sort of remove your religious hat, no?

Amanda Glaze

I think that’s right. I love the term cognitive apartheid. Look at people like Francis Collins, the director of the National Institutes of Health, who is a Christian and says openly that he wishes that science would not contradict what the Bible says, but it does and he recognizes that, and he still chooses to be a believer.

Sean Illing

Neil deGrasse Tyson likes to say that the great thing about science is that it’s true whether you believe it or not. The trouble with this kind of scientific illiteracy is that it genuinely harms these students, who cannot succeed in a society based on science and technology if they don’t understand it.

Amanda Glaze

It’s crucial. And that’s why I tell people this is not a fight for evolution per se. I mean, evolution is a mechanism by which I work with people because if we can hit the most controversial points in the places where they are the most controversial, we can get to that level of conceptual change.

Then imagine what we can do in the places where it’s not as resistant, where it’s not as vocal, where it’s not as taboo. This is a war for science literacy.

Wolbachia doesn’t just infect the blue moon; it’s also found in some 40 percent of species of insects and arthropods, as well as other animals like parasitic nematode worms. Scientists still disagree about whether the various lineages (or “supergroups”) should be classified as a single species or as many separate ones. But however you cut it, Wolbachia is everywhere.

As I’ve written in TheAtlantic before, many scientists are trying to use this omnipresent microbe to stop important tropical diseases like dengue fever, Zika, and elephantiasis. Others, like Hurst, are studying it for its own sake, including the extraordinary ways in which it manipulates its hosts. Sometimes, as in the blue moon butterfly, it kills males outright. In other hosts, it can transform males into females, or even turn females into cloners that can reproduce asexually without needing males at all.

It’s around this time that we see in the fossil record (based mainly on rib and pelvis fossils) a reduction of the size of the gut areas in Homo erectus, the early human species credited with consistently incorporating animal foods into its diet. This species evolved a smaller, more efficient digestive tract, which likely released a constraint on energy and permitted larger brain growth, as predicted by the expensive tissue hypothesis. Yet the increase in brain size we see in the fossil record at about 2 million years ago is basically tracking body size; while absolute brain size was increasing, relative brain size was not. Maybe meat was not completely responsible—so what was?

Perhaps it was the shift from eating antelope steak tartare to barbecuing it. There are hints of human-controlled fires at a few sites dating back to between one and two million years ago in eastern and southern Africa, but the first solid evidence comes from a one-million-year-old site called Wonderwerk Cave, in South Africa. In 2012, Francesco Berna, then of Boston University, and his colleagues reported bits of ash from burnt grass, leaves, brush, and bone fragments inside the cave. Microscopic study showed that the small ash fragments are well preserved and have jagged edges, indicating that they were not first burned outside the cave and blown or washed in, as those jagged edges would have been worn away. Also, this evidence comes from about 30 meters inside the cave, where lightning could not have ignited the fire.

Soon after that, the 790,000 year old site of Gesher-Benot Ya’aqov in Israel yielded evidence of debris from ancient stone tools that had been burned by fire. Nearby to the burnt tools were concentrations of scorched seeds and six kinds of wood, including three edible plants (olive, wild barley, and wild grape), from more than a dozen early hearths. This marks the first time that early humans came back to the same location repeatedly to cook over these early campfires. Hearths are more than just primitive stoves; they can provide safety from predators, be a warm and comforting location, and serve as places to exchange information.

Cooking was unquestionably a revolution in our dietary history. Cooking makes food both physically and chemically easier to chew and digest, enabling the extraction of more energy from the same amount of food. It can also release more of some nutrients than the same foods eaten raw and can render poisonous plants palatable. Cooking would have inevitably decreased the amount of time necessary to forage for the same number of calories. In his 2009 book Catching Fire, primatologist Richard Wrangham postulates that cooking was what allowed our brains to get big. It turns out that using fossil skulls to measure brain size, we see the biggest increase in brain size in our evolutionary history right after we see the earliest evidence for cooking in the archaeological record, so he may be on to something. Modern human bodies are so adapted to cooked foods that we have difficulty reproducing while on an exclusive diet of raw foods. For example, a 1999 study found that about 30 percent of reproductive-age women on a long-term raw-food diet had partial to complete amenorrhea, which was probably related to their low body weight.